Hydroisomerization process



July 25, 1961 H. s. B'LO'CH ET AL ,938

, HYDROISOMERIZATION PROCESS Filed June 18, 1958 2 Sheets-Sheet 1' l I .15 40 45 lsobufane, Weight 0f Total 0 H Figure 2 200 300 ppm Sulfur No HG/ aa awsag ag 4 14 41 Pi /A w /1m Figure N0 Sulfur N0 HO/ /0 :/5' 20 25 50' /s 0bu'/ane, Weigh! 0f Tofa/ 0 H IN V5 N TORS: Harman 5'. Bloch Vladimir Haensa/ United States Patent M 2,998,938 HYDROISOMERIZATION PROCESS Herman S. Bloch, Skokie, and Vladimir Haensel, Hinsdale, Ill., assignors, by mesne assignments, to Universal Oil Products Company, Des Plaines, 111., a corporation of Delaware Filed June 18, 1958, Ser. No. 742,785 20 Claims. (Cl. 260-666) This invention relates to a process for the hydroisomerization of an isomerizable organic compound, and more particularly relates to a process for the hydroisomerization of an isomerizable saturated hydrocarbon. Still more particularly, this invention relates to a process for the hydroisomerization of a less highly branched chain parafiin hydrocarbon to a more highly branched chain parafiin hydrocarbon at hydroisomerization conditions in the presence of hydrogen and a hydroisomerization catalyst comprising a hydrogenation component deposited on an acid-acting support. Along with said hydroisomerization process, the present invention relates to a method for controlling hydrocracking which occurs due to the use of hydrogen in this process along with the hydrogenation component. This hydro-cracking is controlled by the addition of a sulfur compound to the isomerizable organic compound being subjected to hydroisomerization. At the same time maximum hydroisomerization is achieved by the addition of a halogen compound to control hydroisomerization. This dual addition of a sulfur compound and a halogen compound will be described in detail as part of the following specification.

In recent years with the advances in the automotive industry, fuels of relatively high octane ratings have been found to be necessary. Many petroleum refining processes have been provided for the production of such high anti-knock fuels. These processes include alkylation, reforming, catalytic cracking, and high temperature thermal cracking and thermal reforming operations. Other processes which may in one sense be considered auxiliary were developed, for example, isomen'zation, which was employed to produce isoparaifins which subsequently were reacted with olefins to form a high octane number motor fuel fraction, commonly termed alkylate. In addition to the production of one of the reactants for alkylation, isomerization was also utilized to increase the anti-knock quality of saturated hydrocarbons such as paraflins and naphthenes found in selected fractions of gasolines and naphthas. An example of the latter type of operation is a process in which pentane and/or hexane fractions are isomerized to produce isopentane and/or isomeric hexanes which subsequently may be employed as blending agents in automotive and aviation fuels.

In most of the above mentioned isomerization processes, catalytic agents have been employed to efiect the desired molecular rearrangement. These prior art catalytic agents have been employed in what may be termed low temperature processes. Ordinarily the catalytic agents utilized in such processes consist of metal halides, such as aluminum chloride, aluminum bromide, etc., which are activated by the addition of the corresponding hydrogen halide. These catalytic agents are initially very active and eifect high conversion per pass at relatively low temperature. However, the activity of these catalysts is so high that the catalysts accelerate decomposition re- 'Isomerization processes which are carried out or oper 2,993,938 Patented July 25, 1961 actions as well as isomerization reactions with the result that the ultimate yield of isomerized product is reduced considerably. These decomposition or catalytic cracking reactions also considerably increase catalyst consumption by reaction of fragmental material with the catalytic agent to form sludge-like material. In spite of what might have been predicted, these decomposition and/or catalytic cracking reactions cannot be reduced by simply lowering the reaction zone temperature. At temperatures at which satisfactory isomerization reactions are obtained with these prior art catalytic agents, these cracking reactions are pronounced. One means which has been utilized in an attempt to decrease or overcome these cracking reactions is the concurrent utilization of hydrogen along with the isomerizable organic compound being processed. While some improvement in conventional processes has been observed, these prior art processes have not been improved to the extent that they have been widely accepted for use in the petroleum refining indusated with continuous hydrogen addition or in the presence of hydrogen can be termed hydroisomerization processes. In hydroisomerization processes the main reaction which takes place is that of molecular rearrangement of the organic compound being subjected to hydroisomerization. As is the case with prior art catalytic agents, this hydroisomerization reaction is accompanied by certain undesirable decomposition or hydrocracking reactions. We have discovered that these decomposition or hydrocracking reactions can be substantially diminished while at the same time maintaining catalytic activity for hydroisomerization by the concurrent addition to the hydroisomerizationv process of a sulfur compound and a halogen compound. This discovery in conjunction with the utilization of a more recently developed hydroisomerization catalyst comprising a hydrogenation component deposited on an acid-acting support now makes commercial utilization of hydroisomerization a practical reality.

These more recently developed hydroisomerization catalysts all require somewhat higher temperatures to attain catalyst activity than have been utilized heretofore in similar type reactions. The use of such higher temperatures apparently accelerates decomposition reactions at a greater rate than the molecular rearrangements are accelerated. Thus, in the absence of controls, catalytic hydrocracking becomes the predominant reaction thus consuming substantial quantities of feed stock in the hydrocracking process. Modification of such processes by reduction of catalyst activity through the addition of a compound of sulfur not only results in decrease in hydrocracking reactions but also results in substantial or complete loss of hydroisomerization activity by the catalyst. If a different approach to these catalysts is taken, for example, by the addition of a halogen compound (in the absence of a sulfur compound), the lower operating temperatures required to reduce side reactions to an acceptable efiiciency are such that conversion per pass at normal space velocities is too low for economical operation, or conversely, space velocities required for acceptable conversions are too low for economical operation. By the use of the process of the present invention, including addition of both a compound of sulfur and a compound of halogen, along with more recently developed hydroisomerization catalysts, results are obtained which have not been considered possible heretofore.

One embodiment of the present invention relates to a process for the hydroisomerization of an isomerizable organic compound which comprises contacting said organic compound with hydrogen at hydroisomerization conditions in the presence of a hydroisomerization catalyst comprising a hydrogenation component deposited on an acid-acting support, adding during said contacting a sulfur compound to control hydrocracking and a halogen compound to control hydroisomerization, and recovering the resultant product.

Another embodiment of the present invention relates to a process for the hydroisomerization of an isomerizable saturated hydrocarbon which comprises contacting said saturated hydrocarbon with hydrogen at hydroisomerization conditions in the presence of a hydroisomerization catalyst comprising a hydrogenation component deposited on an acid-acting support, adding during said contacting a sulfur compound to control hydrocracking and a halogen compound to control hydroisomerization, and recovering the resultant product.

Another embodiment of the present invention relates to a process for the hydroisomerization of a less highly branched chain paraffin hydrocarbon to a more highly branched chain paraffin hydrocarbon which comprises contacting said less highly branched chain paraffin hydrocarbon with hydrogen at hydroisomerization conditions in the'presence of a hydroisomerization catalyst comprising a hydrogenation component deposited on an acid-acting support, adding during said contacting a sulfur compound to control hydrocracking and a halogen compound to control hydroisomerization, and recovering the resultant product.

A more specific embodiment of the present invention relates to a process for the hydroisomerization of a less highly branched chain paraffin hydrocarbon to a more highly branched chain parafiin hydrocarbon which comprises contacting said less highly branched chain paraflin hydrocarbon with hydrogen at hydroisomerization conditions in the presence of a hydroisomerization catalyst comprising platinum deposited on alumina containing combined halogen, adding during said contacting a sulfur compound to control hydrocracking and a halogen compound to control hydroisomerization, and recovering the resultant product.

One specific embodiment of the present invention relates to a process for the hydroisomerization of n-butane which comprises contacting said n-butane with hydrogen at hydroisomerization conditions in the presence of a hydroisomerization catalyst comprising platinum deposited on alumina containing combined fluorine, adding during said contacting a sulfur compound to control hydrocracking and a halogen compound to control hydroisomerization, and recovering the resultant product.

Another specific embodiment of the present invention relates to a process for the hydroisomerization of n-pentane which comprises contacting said n-pentane with hydrogen at hydroisomerization conditions in the presence of a hydroisomerization catalyst comprising platinum deposited on alumina containing combined fluorine, adding during said contacting a sulfur compound'to control bydrocracking and a halogen compound to control hydroisomerization, and recovering the resultant product.

A further specific embodiment of the present invention relates to a process for the hydroisomerization of n-hexane which comprises contacting said n-hexane with hydrogen at hydroisomerization conditions in the presence of a hydroisomerization catalyst comprising platinum deposited on alumina containing combined fluorine, adding during said contacting a sulfur compound to control hydrocracking and a halogen compound to control hydroisomerization, and recovering the resultant product.

The process ofour invention is particularly applicable to the hydroisomerization of saturated hydrocarbons including acyclic paraffins and cyclic naphthenes and is particularly suitable for the hydroisomerization of straight chain or less highly branched chain paraflins containing four or more carbon atoms per molecule including normal butane, normal pentane, normal hexane, Z-rnethylpentane, B-methylpentane, normal heptane, Z-methylhexane, 3-rnethylhexane, normal octane, Z-methylheptane, 3- methylheptane, 4-methylheptane, etc. Cycloparafiins or naphthenes which may be utilized in our hydroisomerization process should contain at least 5 carbon atoms in the ring such as alkylcyclopentanes and cyclohexanes and include methylcyclopentane, cyclohexane, 1,1-dimethylcyclopentane, 1,2-dimethylcyclopentane, 1,3-dimethylcyclopentane, methylcyclohexane, l,l-dimethylcyclohexane, l,Z-dimethylcyclohexane, 1,3-dimethylcyclohexane, 1,4- dimethylcyclohexane, etc. This process is also applicable to the conversion of mixtures of paratfins and/or naphthenes such as those derived by selective fractionation of straight run or natural gasolines and naphthas. Such mixtures of parafiins and/ or naphthenes include so-called pentane fractions, hexane fractions, heptane fractions, etc., and mixtures thereof. The process of our invention is also applicable to the hydroisomerization of olefins, for example, the isomerization of l-butene to Z-butene, the isomerization of 3-methyl-l-butene to Z-methyl-Z-butene, etc., although obviously not necessarily under the same conditions of operation since the tendency of these olefins to be hydrogenated or polymerized in the presence of hydrogen and the catalyst must be overcome. The process may also be used for the hydroisomerization of alkylaromatic hydrocarbons, for example, the hydroisomerization of ethylbenzene to xylenes, the hydro isomerization of propylbenzene to methylethylbenzenc, etc.

Various hydroisomerization catalysts are utilizable within the generally broad scope of the process of the present invention. These catalysts may be defined as comprising a hydrogenation component deposited on an acid-acting support. The acid-acting support may inherently have this property or its acidacting characteristics may be added thereto either before or after deposition of the hydrogenation component thereon. Suitable supports may be selected from among the different "refractory oxides including silica, alumina, silica-alumina, silicaalumina-magnesia, silica-alumina-zirconia, silica-zirconia, etc. These supports may be naturally occurring or may be prepared synthetically. Other suitable naturally occurring refractory oxides include acid-acting clays such as Filtrol, Tonsil, etc., diatomaceous earths, montmorillonites, etc. Depending upon Whether or not the refractory oxide support is naturally occurring or prepared synthetically, and depending upon the method of preparation, and upon the treatment of the support thereafter, these various supports will have surface areas ranging from about 25 to about 500 square meters per gram. In some of these supports the acid-acting function is inherently present, as stated hereinabove, for example, when silica-alumina or silica-alumina-zirconia is used as the support. The effectiveness of this acid-acting function in such a support is controlled by the quantities of the respective components, and by the treatment of the composites, particularly by calcination, prior to or after compositing the hydrogenation component therewith. The preferred catalysts used in the hydroisomerization zone'in the process of the present invention comprise a hydrogenation component deposited on an acid-acting support.

The hydrogenation component will normally be selected from groups VI(B) and VIII of the periodic table or mixtures thereof. Such hydrogenation components include chromium, molybdenum, tungsten, iron, cobalt, nickel, and the so-called platinum group metals. By a platinum group metal is meant a noble metal,,exclu'ding silver and gold, and selected from platinum, palladium ruthenium, rhodium, osmium, and iridium. These metals are not necessarily equivalent in activity in the catalysts utilized in the hydroisomerization process of the present invention and of these metals, platinum and palladium are preferred, and particularly, platinum is preferred.

The preferred catalyst composition for use in this process comprises platinum deposited on alumina containing combined halogen, and preferably combined fluorine. The alumina is preferably synthetically prepared substantially anhydrous gamma-alumina of a high degree of purity. The methods of preparation of such synthetic gamma-aluminas are well known. For example, they may be prepared by calcination of alumina gels which are commonly formed by adding a suitable reagent, such as ammonium hydroxide, ammonium carbonate, etc., to a salt of aluminum such as aluminum chloride, aluminum sulfate, aluminum nitrate, etc., in an amount to form aluminum hydroxide which upon drying and calcination is converted to gamma-alumina. It has been found that aluminum chloride is generally preferred as the aluminum salt, not only for convenience in subsequent washing and filtering procedures, but also because it appears to result in the most active catalytic composite. Alumina gels may also be prepared by the reaction of sodium aluminate with a suitable acidic reagent to cause precipitation thereof with the resultant formation of aluminum hydroxide gel. Synthetic aluminas may also be prepared by the formation of alumina sols, for example, by the reaction of metallic aluminum with hydrochloric acid, which sols can be gelled with suitable precipitation agents such as ammonium hydroxide, followed by drying and calcination. In the preferred embodiment, these synthetically prepared aluminas will contain from about 0.01% to about 8% combined halogen based on the weight of the dry alumina, the combined halogen preferably being fluorine. These halogenated aluminas may be prepared in various manners, for example, by the addition of a suitable quantity of hydrofluoric acid to the alumina gel prior to drying and calcination thereof. In another manner, ammonium fluoride can be added to alumina gels thus yielding an alumina having the desired quantity of fluorine combined therewith. When the synthetically prepared alumina is prepared from aluminum chloride, it is sometimes advantageous and/or desirable to minimize the washing thereof to retain a desired amount of chlorine combined with the alumina. In many of the above instances when the alumina is prepared from an alumina sol or an alumina gel, the resultant product is calcined at a suflicient temperature to convert the product into gamma-alumina. While the resultant aluminas may contain relatively small amounts of water of hydration, less than one mol of water per mol of alumina, gamma-alumina containing combined halogen is the preferred synthetically prepared alumina for use as the support for the preferred catalysts in the process of the present invention.

The preferred synthetically prepared gamma-alumina, as hereinabove set forth, then has a hydrogenation component, particularly a platinum group metal, combined therewith. The hydrogenation component, particularly a platinum group metal, and still more particularly platinum, may be composited with the alumina in any of many Well known methods. For example, an ammoniacal solution of chloroplatinic acid may be admixed with the alumina followed by drying. In another method, the chloroplatinic acid in the desired quantity can be added to an alumina gel slurry followed by precipitation of the platinum on the alumina by means of hydrogen sulfide or other sulfiding agents. While the quantity of platinum composited with the alumina is not critical, for economic reasons the amount of platinum is kept at a minimum. Thus larger amounts of platinum do not cause detrimentral effects. While the quantity of platinum composited with the alumina is not critical it is generally preferred to utilize from about 0.01% to about 2% 'by weight of platinum based on the dry alumina. In

.tremely temperature sensitive.

another embodiment, the alumina and platinum can be composited by co-precipitation techniques. In such a case, an aqueous solution of a platinum salt is admixed with a solution of an aluminum salt followed by the addition thereto of a precipitation agent which will cause coprecipitation. The resultant gel can then be dried and calcined to form an alumina-platinum composite which can be formed into the desired size particles.

While the form of the catalyst comprising a hydrogenation component deposited on an acid-acting support is not critical, generally it is preferred to utilize macro particles so that the total composite may be used as a fixed bed in a reaction zone. Thus it is desirable to form the synthetic alumina containing combined halogen, either before or after the platinum is composited therewith into pellets, for example of A inch by 5 inch size or inch by 4; inch size, etc. This is accomplished readily by grinding the dried alumina gel to a powder followed by pilling thereof by known methods. Alternatively the particles may be utilized in the form of dried gel, or they may be irregularly shaped particles such as result from extrusion. The composites of hydrogenation components deposited on acid-acting supports, for example, platinum deposited on alumina containing combined halogen, are somewhat hygroscopic and if it is necessary to store them it is generally preferred to do so in an atmosphere of reduced humidity.

The process of this invention is directed to the hydroisomerization of organic compounds in which molecular rearrangements are accomplished at hydroisomerization conditions. While the use of hydrogen in prior art isomerization processes has been disclosed as a cracking suppressor it is felt that the hydrogen pressure or partial pressure is a much more important variable in the process of this invention. This use of hydrogen is based on the finding that hydrogen apparently plays an important role in the mechanism of the hydroisomerization reaction and its utilization in the hydroisomerization reaction is more than simply as a cracking suppressor. In this hydroisomerization process sufficient hydrogen should be utilized so that the hydrogen to hydrocarbon molar ratio of the reaction zone feed will be within the range of from about 0.2 to about 10. When smaller quantities of hydrogen are utilized, and even when quantities of hydrogen within the above range are utilized in the absence of added sulfur compounds, the catalyst rapidly deactivates and cracking reactions become prominent. This obviously illustrates that the hydrogen is not a cracking suppressor with these catalysts. Furthermore, the use of quantities of hydrogen in excess of the 10:1 molar ratio hereinabove set forth are detrimental since the hydroisomerization reaction can be stopped completely by this means. This last mentioned effect illustrates the fact that the hydrogen plays a more important role in these hydroisomerization reactions than that merely of a cracking suppressor. The hydrogen may be supplied from any convenient source and will generally be recycled within the process so that hydrogen consumption will be for all practical purposes negligible. The hydrogen utilized may be purified or may be diluted With various inert materials such as nitrogen, methane, ethane, propane, etc.

The catalyst utilized in the process of this invention has high hydroisomerization activity and is capable of rearranging saturated hydrocarbons at relatively mild conditions. Processes have recently been proposed for the isomerization of pentane and/or hexane utilizing certain noble metal containing catalysts. These processes are all carried out at relatively high temperatures and are ex- In contrast, processes for the isomerization of saturated hydrocarbons utilizing Friedel-Crafts metal halides promoted by hydrogen halides have been proposed for operation at relatively low temperature, for example, from about 50 to about C. Decomposition reactions in such processes, as hereinabove set forth, are very pronounced. Catalyst concompound of sulfur and a compound of halogen.

sumption is high and catalyst life is low. While the catalyst utilized in the process of the present invention requires temperatures intermediate between those which have previously been proposed for operation, the economic balance between the additional heat requirement and catalyst life is very favorable for the process of the present invention.

The operating conditions to be employed will dependupon the particular compound being subjected to hydroi'sor'nerization and generally the temperatures will range from about 250 C. to about 450 C. although temperatures within the more limited range of from about 325 C. to about 425 C. are preferred. The pressure utilized will range from about 50 pounds per square inch to about 1500 pounds per square inch. Pressures within the range of from about 300 pounds per square inch to about 800 pounds per square inch appear to be most favorable for the hydroisomerization of saturated hydrocarbons in the process of the present invention.

As set forth hereinabove, the process of the present invention utilizing the above described catalyst is particularly adapted for a so-called fixed bed type process. In such a process, the compound or compounds to be hydroisomerized are passed in either an upward or downward flow over the catalyst along with hydrogen. The reaction products are then separated from the hydrogen, which may be recycled, and subjected to fractionation and separation of the desired reaction products. Recovered starting material is recycled so that the overall process conversion is high. In such processes'the hourly liquidspace velocities which are defined as the volume of reactants per hour per volume of catalyst will be maintained 'within the general range of from about 0.25 to about and preferably within the range of from about 0.5 to about 5. Another means of elfecting the hydroisoinerization reaction of the process of the present invention is to employ a fluidized bed of catalyst wherein the reactant or reactants are passed upwardly through a bed of the catalytic material at a suificient rate to maintain the indiivdual particles of catalyst in a state of hindered settling. However, the rate of passage of reactants through the bed is not so great as to suspend the catalytic material in the stream of compound being subjected to hydroisomerization and carry the catalyst out of the reaction zone. As is readily apparent somewhat smaller size particles than hereinabove described are suitable for such a modified operation. If desired, the catalyst will be utilized in the form of so-called micro particles and the process may be eflected in a two zone fluidized transfer process. In such a process when it is desired to regenerate the catalyst or to reactivate it by other means, the catalytic material may be suspended in a gas stream and conveyed to a second zone wherein it is contacted with reactivating material, after which the reactivated catalyst is returned to the reaction zone wherein it is utilized to effect further conversion reactions. Another suitable two zone system may be the use of a moving bed wherein a desired bed of catalytic material slowly descends through the reaction zone, is discharged from the lower portion thereof into a reactivation zone from which it is again transported to the top of the moving bed in the reaction zone to descend through the zone effecting further reactions in transit. Regardless of the particular operation employed, the products are fractionated or otherwise separated to recover the desired product and to separate unconverted material which may be recycled.

Hydrogen in the eflluent product likewise is separated and preferably is recycled.

Asset forth hereinabove the hydroisomerization process of the present invention is controlled by the simultaneous addition to and with the feed to the process of a Various compounds of sulfur are utilizable as additives to "control the hydrocracking which takes place without such addition. Preferably, these co'mpoundsof sulfurshould :11

boil within the approximate range of the organic compound being subjected to hydroisomerization. Furthermore, various classes of sulfur compounds are utilizable as a means of furnishing the sulfur including hydrogen sulfide, mercaptans, thioethers, disulfides, thiophene and its derivatives, thioacids, etc. Typical suitable and utilizable compounds of sulfur within the above classes include methyl mercapt'an, ethyl mercaptan, normal propyl mercaptan, isopropyl mercaptan, normal butyl mercaptan, isobutyl mercaptan, secondary butyl mercaptan, tertiary butyl mercaptan, amyl mercaptans, hexyl mercaptans, etc., dimethyl sulfide, methyl ethyl sulfide, diethyl sulfide, ethyl propyl sulfide, dipropyl sulfide, etc., dimethyl disulfide, ethyl methyl disulfide, diethyl disulfide, ethyl propyl disulfide, dipropyl disulfide, etc., thiophene, methylthiophene, ethylthiophene, dimethylthiophenes, sulfur chloride, sulfur dichloride, etc. As set forth hereinabove, hydrogen sulfide may be utilized. In addition, and in a like manner, carbon disulfide may be utilized. All of these compounds of sulfur, and thus the preferred compounds of sulfur for use in the process of this invention, are characterized by the sulfur having a formal charge of zero. These compounds of sulfur are added in an amount sufficient to control hydrocracking, which amount is usually within the range of from about 0.0001% by weight of the feed to about 0.1% by weight of the feed, or from about one to about 1000 p.p.m. based on the feed.

Addition of a compound of sulfur, as set forth hereinabove, reduces the hydrocracking activity of the catalysts utilized in this process. However, this hydrocracking is not the only catalyst activity which is reduced. Hydroisomerization activity is likewise reduced substantally. Thus, when utilizing a compound of sulfur to control hydrocracking, it has been found necessary to utilize concurrently therewith a halogen compound to control hydroisomerization activity. With the utilization of both a compound ofsulfur and a halogen compound, results are attained which cannot be obtained by the utilization of either compound alone. Various compounds of halogen may be utilized to control the hydroisomerization reaction as set forth above. Typical suitable and utilizable compounds include C1 Br I hydrogen halides such as hydrogen fluoride, hydrogen chloride, hydrogen bromide, alkyl halides such as methyl fluoride, methyl chloride, methyl bromide, ethyl fluoride, ethyl chloride, ethyl bromide, ethyl iodide, normal propyl fluoride, normal propyl chloride, normal propyl bromide, isopropyl fluoride, isopropyl chloride, isopropyl bromide, normal butyl fluoride, normal butyl chloride, normal butyl bromide, isobutyl fluoride, isobutyl chloride, isobutyl bromide, secondary butyl fluoride, secondary butyl chloride, secondary butyl bromide, tertiary butyl fluoride, tertiary butyl chloride, tertiary butyl bromide, amyl fluorides, amyl chlorides, amyl bromides, etc., dihaloalkanes such as dichloromethane, ethylene dichloride, etc., polyhaloalkanes such as trichloromethane, carbon tetrachloride, dichlorobromomethane, difluorodichloromethane, etc. Other compounds of halogen which may be utilized include haloaromatic compounds, acyl halides, sulfur halides, etc. These compounds of halogen which are added concurrently with the compound of sulfur are added so that they are present in the reaction zone in an amount of from about 0.000l% by weight of the feed to about 0.1% by weight of the feed, or in other words in an amount of from abount one to about 1,000 p.p.m. based on the feed. As will be set forth further in the examples, the exact quantity of added compound of sulfur and compound of halogen is not as important as is the fact that both compounds are present thus yielding halogen and sulfur which are present in the reaction zone along with the feed. The compound of sulfur apparently has an immediate and drastic effect upon catalyst activity and in this manner can be'utilized as a directcontrol of hydrocracking activity of the catalyst. In the, presence of the compoundof sulfur, the compound of halogen increases only hydroisomerization activity. The combination eflect of these two additives is then to obtain high conversions per pass coupled with high ultimate yields. Furthermore, al though the compound of sulfur must be added continuously, the compound of halogen may be added continuously or intermittently.

This invention is illustrated by the following examples which are introduced for the purpose of illustration with no intention of unduly limiting the generally broad scope of this invention. These examples were carried out in a bench scale apparatus. The reactor used consisted of a stainless steel tube of about one inch inside diameter and about 50 inches long placed in an electrically heated aluminum bronze block furnace. The reactor was equipped with a 4 inch outside diameter thermowell for measurement of reaction temperature. The upper section of the reactor contained a spirally grooved stainless steel preheat section while the space. below the catalyst bed was filled with stainless steel spacers. The hydrocarbon was fed to the reactor using a plunger type charge pump at rates as shown in the examples. The hydrogen charge to the reactor was from a high pressure hydrogen cylinder. The reaction products were condensed, cooled to in oil, and then in an aqueous solution of ammonia; The washed spheres were then transferred to a drier, dried at about 250 C. and calcined at about 600 C. The synthetically prepared alumina spheres containing 4.0% fluorine were impregnated with a dilute ammoniacal solution of chloroplatinic acid. The amount of platinum in this solution was adjusted so that the final composite contained 0.375% platinum by weight based on the dry alumina. The thus impregnated composite was calcined 10 in air at a temperature of about 500 C. A sufiicient quantity of this catalyst was prepared for use in the examples as set forth hereinafter.

A 150 cc. quantity (88.0 grams) of the above prepared composite was placed as a fixed bed in a reaction tube and tested for activity for the hydroisomerization of normal butane to isobutane. The normal butane utilized was that available commercially as chemically pure n-butane and prior to use it was dried over Drierite. Conditions utilized in this example included a pressure of 500 p.s.-i.g., a hydrogen to hydrocarbon mol ratio of about 2.0, hourly liquid space velocities of about 2.0 and about 4, and various temperatures. The results of nine spaced two hour periods utilizing the above catalyst are presented in the following Table I:

Period N o Charge Stock Catalyst On Stream, Hrs Conditions:

Pressure, p.s.i.g Temperature, 0

Block Catalyst, 2 SV Ratio, 112/ Charge.

Rates:

Charge, cc./Hr. at 60 F..." Recycle Gas, s.c.f./Hr. H2 Addition, s.c.t./Hr

Products, mols/lOO mols 04H;

charged:

C1 and C3 Total Hydrocracking. 1C4H1o DQ4Hrn Total Recovery, Wt. Percent Percent Iso C4 in Total 04,

Table I HYDROISOMERIZATION 0F O.P. n-BUTANE IN THE ABSENCE OF SULFUR OR HALOGEN CF. n-Butane (Drierite dried) 0.375% Pt, 4% F, remainder A110;

PC Ultimate Yield, Wt. Percent.

1 To maintain plant pressure.

room temperature, and a phase separation was effected in a high pressure receiver. The liquid product was collected, stabilized to remove low boiling hydrocarbons, and the desired boiling range reaction products analyzed by vapor phase chromatographic or infrared spectrographic techniques.

EXAMPLE I From the above results, it can be seen that hydroisomerization of the n-butane was attained throughout the temperature range utilized, that is, from 350 C. to 430 C., and utilizing liquid hourly space velocities of about 2 and about 4. At 350 C., the product contained 7.7

mol percent isobutane at about 2 liquid hourly space velocity. The amount out isobutane increased with increasing temperature from period 1 through period 5 as the temperature was raised to 430 C. Maximum isobutane content of the product was 32.5% at 430 C.

Total hydrocracking decreased over the same periods from an initial 32.4 mol percent down to 14.5 mol percent. At 430 C., equilibrium calculations indicate the product should contain from 40 to 45 mol percent isobutane.

7 Thus, the activity of the catalyst utilized was notsufliciently high in the absence of catalyst promoters. Periods 6, 7, 8 and 9 show the effect of increasing liquid hourly space velocity and hydrogen to hydrocarbon mol ratio while at the same time, decreasing the temperature from 43G C. to 370 C. The effect was one of merely decreasing conversion without any real gain in reaction efficiency. These results show how sensitive pure n-butaue is to hydrocracking. In the absence of a compound of sulfur and a compound of halogen, substantial conversion of n-butane to isobutane was not attained and hydrocracking of the n-butane to lighter and heavier materials was a prominent reaction.

EXAMPLE II Table II is higher in the presence of sulfur than in its absence as shown by the results in Example I.

EXAMPLE 'III This example illustrates the effect of the addition of chlorine as hydrogen chloride in quantities varyingfrom 100 to 300 parts per million based on the feed to chemically pure n-butane during the hydroisomerization of the n-butane. This example was carried out in the manner described hereinbefore utilizing a l00.cc.,(58.4 grams) sample of the same catalyst described in Example I. Conditions utilized included a pressure of Y500 p.s.i.g., a hydrogen to hydrocarbon .mol ratio of about 2.0, a liquid hourly space velocity of about 1.0, and various temperatures. The results of eleven two hour test periods are presented in the following Table III.

Because of the addition of hydrogen chloride, the experiments set .forth in the above table were begun at a lower temperature, 200 C., in order to approach conversion temperatures without running into excessivehydro- HYDROISOMERIZATION OF n-BUTANE CONTAINING 0.02 WEIGHT PERCENT SULFUR AS THIOPHENE Period No 1 2 3 4 5 6 7 8 9 Charge Stock 0.1. n-Butane and 0.02 Wt. Percent S as Thiophene Catalyst 0.375% Pt, 4% F, remainder A110;

On Stream, Hrs 1011 -16 -21 -26 -31 -36 -41 -46 -51 Conditions:

Pressure, p.s.i.g 500 500 500 500 500 500 500 500 500 Temperature, 0.-

Block 340 350 360 370 380 390 400 410 420 371 380 391 402 413 424 LHSV 1.0 1.0 0. 99 1.00 0.94 0. 96 Ratio, Hz/Charge 1.90 1. 87 1. 97 1. 99 2.10 2.10 01 a1 1. 75 1.71 1.79 1.62 1. 79 1.68 Rates:

Charge, GIL/Hr 101 93 100 100 99 100 94 96 Hydrogen, s.e.f./Hr 1. 62 1. 58 1.62 1. 52 1. 49 1. 56 1. 59 1. 56 1.

Products, mols/lOO mols C4Hio charged:

0 and O 1.8 3.4 7.0 12. 9 C2 and C2.- 1. 3 2.0 4.1 6. 5 Cs and C5 I 0.9 0.4

Total Hydroeraeking. 3. 1 6. 3 11. 5 19. 4 1-C4H1n 14. 8 19.1 27. 5 31. 7 nC|H1o-- 82.1 74. 6 61.0 48. 9

Total 100 100 100 100 Recovery, Wt. Percent 103.1 109. 9 106.6 93. 4 Percent 150 C1 in Total 04,

VPO 1.4 1. 9 4.8 6.2 9. 5 15. 3 20.4 31.1 39. 3 Ultimate Yield, Wt. Percent 77. 2 73. 6 82. 7 75. 2 70. 5 62. 0

From Table II, it is observed that the isobutane in the total C fraction increases from 1.4% at 340 C. to 39.3% at 420 C. Total hydrocracking in periods 1 through 3 was negligible and then hydrocracking increased progressively from 1.8% to 19.4% as the .temperature was progressively raised in periods 4 through 10. In comparison to the results described in Example I, .it appears that the sulfur effectively decreases the hydrocracking activity of the catalyst. For example, at 350 C., in the absence of sulfur, 32.4 mol percent hydrocracking was observed in comparison to none in the presence ofsulfur. At 370 C., in the absence of sulfur, total 'hydrocracking equals 22.2 mol percent in comparison to 1.8 mol percent in the presence of sulfur. At 390 C., in the absence of sulfur, total hydrocracking equaled 19.1 mol percent in comparison to 3.1 mol percent in the presence of sulfur. At 410 C., in the absence of sulfur, total hydrocracking equaled 17.0 mol percent in comparison to 11.5 mol percent in the presence of sulfur. -At-temperatures up to'420 C., the results obtained and presented inthis example show that reaction efliciency cracking at the beginning. Thus, for the first six periods, substantially no conversion was observed. Conversion of n-butane to isobutane began at 320 C. and increased from 3.7 mol percent isobutane of the feed at this temperature to 36.4 mol percent at 400 C. During this same temperature spread, total hydrocracking increased from about 1 mol percent up to about 7.3 mol percent at 400 C. The reaction efficiencies at high conversions in these experiments were much higher than had previously been observed and described in Examples I and II. A reaction efficiency of somewhat over was obtained in the temperature range of from about 340 C. to about 380 C. At 380 C., the conversion of n-butane to isobutane was 35.8 mol percent with a reaction efiiciency of 89.5%. At the reaction temperature of 400 C., hydrocracking increased so that the reaction elficiency decreased. At this temperature, very little additional isobutane appeared in the product, indicating that maximum conversion for this catalyst was being approached between 380 C. and 400 C., andthat the ctficiency already had begun -to drop off.

T able III HYDROISOME'RIZATION OF n-BUTANE CONTAINING 0.01, 0.02 ANDOLOS WEIGHT PERCENT OHLORiN-E AS HYDROGEN oELoRiDE Period No 1 2 3 4 5' 6 7 8 9 10 11 QP. n-Butai1e (Sodium dried) 0.375% Pt, 4% F, remainder A1701 01 51152111115 4-5 11-12 1617 21-22 26-27 31-32 36-37 41-42 46-47 51-52 06457 Conditions: 1

Pressure, p.s.i.g' 500 500 500 500- 600 500 500 600 500 600 500 Temperature,

Block 200 221 240 260 280 300 320 340 360 380 400 Catalyst, 2" 198 219 240 260 279 300 321 340; 1 361 382 406 0.96 0. 94 0. 97 1. 00 1. 01 1. 01 l. 02 1. 05 1. 04 1. 03 1.03 Ratio, Hn/Charge- V 1 Apparent Inlet (2. 0) (2.0) (2. 0) (2.0) (2.0) (2. 0) 2.04 1. 81- 2. 07 1. 96 1. 90 R t Actual Inlet 2.27 2.16 2.28 2. 01' 1.44

Charge, 0c./Hr 96 94 97 100 101 101 102 105 104 103 103 Hydrogen, s.c.f./Hr. 1. 60 1. 60 1. 65 1. 65 1. 60 1.60 1. 65 '1. 51 1.71 1. 60 1. 55 O1,p.p;m 300' 200 200 100' 100 200 200 100 100 100 1 100 Products, mols/100 mols O4H1o charged:

0 511504 0.6 0.8 1.7 2.4 5.7 02 and O2--- 0.4 03 0. 6 1.0 1.6 05511501 0.4 0.8

, Total Hydrorr i 1.4 1.1 2.3- 4.2 7.3 i-Cfilm 1 1. 3.7 12.0' 1 27.1; 35.8. 36.4 nO1Hm 94.9 85.3 70.5 V 50.0 55.

Total 100 100 100 100 100 Recovery WtpP 93.6 84.6 9555 85.3 Percent 150 O in Total 04,.

VP 3. 8 12. 7 27. 7 s7. 4 59.3 Ultimate Yield, Wt. Percent- 72. 5 92. 0' 92. 2 89. 5' 83.3

quantities of 100 p.p.m. and '200p.p.m-. The 5515 5555 of sulfur utilized was thiophene which'wasadded 015 n-butane in a quantity so that it contained 200 -p.p.n1-. of sulfur. Conditions utilized included apressureof 500' p:s.i;g., a hydrogen to hydrocarbon mol ratio of about 2.0, liquid hourly space velocities of about 1 ".0 and'about 0.25, and various temperatures. This example was carried out in the manner described hereinaboveutiliiing a 100 05. (58.0 grams) sample of the same catalyst'described in Example I. Theresults of seven two" hour test periods and two four hour test periods are presented in the following Table IV:

Table IV HYDROISOMERIZATION or n-B'UTANE CONTAINING 0.022.501.1 02 AND' 0.01%- 111'01) 0:027;

OHLORINE P5555 195 1 2 a 4 5 '5 7 V a 0 9 Charge Stock 0.1. n-Butane (Sodium dried, 200 p.p.m'..S asvthiophene added to't'ed) Catalyst 0.375% Pt, 4.0% F, remainder A140;

'8'J'i%1t1am,Hrs -75 -81v -85 -91 -95 101-102 115-115j"1"25'-1a0f'140-114' on ODS: V

Pressure, p.s.i.g 600; 600.- 500 '600 600 500 '500 500 500' Temparature,0 1 v 100 99 101 98; 99; 102 i 101. 25- 25 1.51 1.50 1.55 1. 55 1.50 1.51 1. 55. 0.41. 0. a9 01, p.p.m 200 100 100 100 100 100 200 100- 100 Products mols/100 mols O4H15 charge 1 4.7 11.1 29.2 5.5 3.2 2.5 5.5 8.2 1.4 4.1 11.1 2.8 0.9 0.7 2.7 1.0 0.4 2.2 4.5 1.4 0.4, 1.4 0.8 1:4

' 5.5 17.4 449 10.8 4.5 4.7 10.1 55 V40. 5 32. 5 22. 1 95. 2 s9. 5 40.9 37. 8 40.4 52.9 50.0 33.0 53.0 55.9 54.4 52.1 54.0 Total -Q 100 100 100 100 100 p '100 100 100' 100 Recovery, Wt. Pei-5555---"... 101.4 943 100 10s 5 97.0 98.0 95.8 Percent O4 in Total 04,

VPO 38.2 43.4 39.5 40.1 40.5 41.5 42.9 42.0 42.8 Ultimate Yield, Wt. Percent.. 87.4 85.2 55.2 33.0 77.0, 89.8 89.7 78.0 87.8

The results in the above table show the attainment of high conversion of n-butane to isobutane under conditions wherein hydrocracking is minimized. For example, period 6 shows an isobutane concentration of 41.5% in the total C fraction with a reaction efiiciency of 89.8%. This can be compared with Table III, period 10 in which the isobutane concentration was 37.4% in the total C, fraction with a reaction efiiciency of 89.5%. A temperature differential of 20 C. was necessary to attain the result shown in Table III in comparison to this period 6 of Table IV. In other words, the experimental period 10 in Example III required a temperature of 380 C. in comparison to a temperature requirement of 360 C. when utilizing both sulfur and halogen addition. In period 9, Table H1, at 360 C. the isobutane concentration was only 27.7% in the total C, fraction compared with the 41.5% obtained by the use of the process of this invention as shown by period 6, Table IV. This observation is surprising since it is known that the presence of sulfur alone diminishes hydrocracking and the presence of a halogen compound alone increases isomerization activity. The combined efiect appears to be synergistic since the combination of the two additives results in more than simply diminishment of hydrocraoking activity and increase in isomerization activity.

The results obtained in Examples I, II, HI and IV, and in addition, results of some other similar experiments have been plotted on graphs. This has resulted in the smooth curves shown in FIGURES 1, 2, 3 and 4 of the attached drawings.

FIGURE 1 is a curve obtained by plotting some of the data from Example I and shows that the extrapolated theoretical yield of isobutane (at zero isobutane in the total fraction) which can be obtained in the absence of a compound of sulfur and a compound of chlorine in the presence of the hereinabove described catalyst and at the process conditions utilized is about 73 As reaction zone severity is increased, for example by increasing temperature or decreasing liquid hourly space velocity, the conversion of n-butane to isobutane increases but the ultimate yield of isobutane which can be obtained drops off rapidly.

FIGURE 2 shows the effect of the addition of a compound of sulfur. At zero n-butane conversion, the theoretical yield of isobutane which can be obtained approaches an extrapolated value of 77%. As the quantity of isobutane converted is increased, the ultimate yield of isobutane which can be obtained decreases rapidly. However, these results are obviously better than those shown in FIGURE 1 for at 30% isobutant in the total 0 H fraction in the absence of a compound of sulfur and a compound of halogen, the ultimate yield is about 61% isobutane, whereas at the same 30% isobutane content in the total 0., fraction and in the presence of a compound of sulfur, the ultimate yield increases to about 71%. This shows the eifect of the compound of sulfur in decreasing the hydrocracking reaction.

FIGURE 3 shows the effect of the addition of a compound of halogen in the absence of a compound of sulfur. The theoretical ultimate yield of isobutane at zero isobutane content in the total C, fraction is in the neigh borhood of 95%. Alt conversion conditions, as reaction zone severity is increased, the added halogen compound results in increased n-butane conversion to isobutane. At about 20% isobutane in the total C H 'fraction, the ultimate yield begins to drop otf and as equilibrium is approached, the ultimate yield is about 85%. This large effect of the addition of a compound of halogen is obvious at 30% isobutane in the total 0., fraction where an ultimate yield of about 92.5% can be obtained. is almost 30% higher than with no compound of halogen or compound of sulfur added and about 20% higher than the result obtained by the addition of a compoundof sulfur in the absence of a compound, 0 11 8 16 Equilibrium conditions in the temperature ranges explored are from about 40% to about 45% isobutane in the total C, product. The rapid hydrocracking which takes over at near equilibrium conditions is obvious from FIGURE 3. Most of the data utilized in FIGURE 3 are presented hereinabove as part of Example III.

FIGURE 4 shows the efitect of the simultaneous addition of both a compound of sulfur and a compound ,of halogen. The data for FIGURE 4 is partly presented above in Example IV and is partly taken from other similar experiments. The theoretical ultimate yield at zero isobutane content in the total C H fraction is about the same as was true in FIGURE 3. At 20% isobutane in the total 0 H, fraction, the ultimate yield of isobutane is about 94%, also very similar to the result shown in FIGURE 3. Likewise, at 30% isobutane in the total C H fraction, the ultimate yield is about 93%, about the same as shown in FIGURE 3. However, as equilibrium conditions are approached, where the significant increase in isobutane conversion must be achieved to make a process commercially economical, the efiect of simultaneous addition of both a compound of sulfur and a compound of halogen is readily apparent. For example, FIGURE 4 shows an ultimate yield of about 92.5 at 40% isobutane in the total C H product. FIGURE 3 shows an ultimate yield of 85% at 40% isobutane in the total C H product. This increment of 7.5% is extremely important. At equilibrium, the ultimate yield drops off rapidly with further increase in reaction severity in a manner similar to that shown in FIGURE 3. This effect is one of cracking of both n-butane and isobutane at approximately the same rate and at reaction zone severities higher than necessary or desirable.

A comparison of all four figures shows that maximum hydroisomerization conversion and highest ultimate yield is obtained by the process of the present invention in which simultaneous additon of a compound of halogen and a compound of sulfur is carried out. The results obtained and illustrated in FIGURE 4 cannot be obtained in any of the other procedures, since without both additives hydrocracking of the feed stock takes over prior to attainment of maximum conversion of n-butane to isobutane at equilibrium conditions. These results further illustrate that although the addition of small amounts of a compound of sulfur to the feed suppresses the hydrocracking activity and affords an operable process insofar as isomerization efiiciency is concerned, the addition of a compound of halogen as well as a compound of sulfur provides a more active catalyst and permits operation at lower temperatures for a given conversion and at higher conversions for a given efficiency.

EXAMPLE V contained 200 p.p.m.of sulfur. The compound of halogen utilized was hydrogen chloride and it was used in quantities of 100, 200 and in one case, 300, and another case, 400 parts per million up to 160 hours on stream, after which the addition of the compound of halogen was stopped. Conditions utilized included a pressure of 500 -p.s.-i.g.,- hydrogen to hydrocarbon mol ratios of about 2.0 and 0.5, liquid hourly space velocities of about 0.25, 1.5 and 3.0, and temperatures of 360 and 380 C. This I example was carried out in the manner described hereinabove utilizing a cc. (58.0 grams) sample of the same catalyst described in Example I. The results of six test periods are presented in the following Table V:

Table V I-IYDROISOMERIZATION OF n-BUTANE CONTAINING 0.02% SULFUR AND WITH INTER- MIITENT ADDITION OF A COMPOUND OF HALOGEN Period No 1 2 3 4 5 6 Charge tock O.P. n-Butane (Sodium dried, 200 ppm. S as thiophene added to feed) atalyst 0.375% Pt, 4.0% F, remainder A110,

on tream, Hrs 126-130 140-144 188-199 255-257 306-308 332-334 Conditions:

Pressure, p.s.i.g 500 500 500 500 500 500 Temperature, 0

Block 3.59 341 300 360 360 380 Catalyst, 2"- 361 341 365 364 363 383 HSV 0. 26 0. 26 1. 47 1. 46 1. 48 3. 00 Ratio, Hu/Ohargepparent Inlet 1. 95 1. 86 1. 96 2. 01 1. 95 0. 52 R t Actual Inlet 3. 58 2.91 2.09 2.16 1. 96 0.54

a es:

Charge, cc./Hr 26 26 147 146 148 300 Hydrogen, s.c.f./Hr 0. 41 0. 39 2.29 2.40 2. 29 1.23 p-nm 100 100 0 0 0 0 Products mols 100 mols O H char d:

01 arid Cal 4 ge 6.6 3. 2 1. 7 2.5 2. a 1.3 G: and o..-

2. 7 1. 0 0. 7 1.6 1.1 0. 4 3 Ca and Us 0.8 1. 4 0. 1

Total Hydroeracking 10. 1 5. 6 2. 4 4. 1 3. 6 1. 8 04H1o 37. 8 40. 4 36. 4 33. 9 32. 1 29. 7 4 10--- 52. 1 54. 0 61. 2 62. 0 64. 3 68. 5

Total 100 100 100 100 100 100 Recovery, Wt. Percent 98. 4 96. 8 99. 2 100. 1 101. 8 97. 7 Percent Iso O4 in Total 04, VPC. 42. 0 42. 8 37. 3 35.3 33.3 30. 2 Ultimate Yield, Wt. Percent 78. 9 87. 8 93. 8 89. 2 89. 9 94. 3

The results in the above table show the attainment of high conversion of n-butane to isobutane under conditions wherein hydrocracking is minimized. After 160 hours of operation, during which hydrogen chloride was added, and during which a conversion of about 37% per pass of n-but'ane to isobutane was reached at 360 C., at a liquid hourly space velocity of 1, at 500 p.s.i.g., and at a hydrogen to hydrocarbon mol ratio of about 2, the hydrogen chloride addition was terminated and the hydroisomerization activity of the catalyst persisted essentially u-ndiminished for at least another 170 hours. During this time the rate of loss of hydrogen chloride from the catalyst dropped to about 1 milligram per hour per hundred grams of catalyst. It is evident that if this slight loss were replenished, periodically or intermittently, the activity of the catalyst would continue almost indefinitely. After 334 hours of use, the carbon content of the catalyst was only 0.16% by weight indicating little or no loss in activity due to this factor.

EXAMPLE VI This example illustrates the hydroisomerization of a hexane fraction utilizing another sample of the same catalyst described in Example I. The hexane fraction feed stock contained Zero mol percent 2,2-dimethylbutane, 9.1 mol percent 2,3-dimethyibutane and 2methylpentane, 11.8 mol percent 3-methylpentane, 53.9 mol percent nhexane, 18.1 mol percent methylcyclopentane, 1.9 mol percent cyclohexane, and 5.2 mol percent benzene. A suflieient quantity of thiophene was added to this feed stock. so it contained 0.02 weight percent (200 parts per million) sulfur. This feed stock was processed over the above catalyst, in a manner similar to that described hereinabove, at 500 p.s.i.g., a 2:1 hydrogen to hydrocarbon mol ratio, at 1.0 liquid hourly space velocity and at 340 C. During the run, sufiioient hydrogen chloride was added so that hydrogen chloride addition was 280 parts per million based on the fresh feed.

Product recovery was 97.7 weight percent and 100.9 volume percent. The debutanizer overhead gas, which is a measure of hydrocracking, was 85 standard cubic feet per barrel. This amount of gas is equivalent to 2.3 weight percent based on the feed.

The F-l-l-S cc. octane number of the product Was 96.9

in comparison to an F1+3 cc. octane number of 80.6

for the fresh feed. Isohexanes in the total C product were 70.6 weight percent in comparison to about 21- Weight percent in the fresh feed. The 2,2-dimethylbutane content of the product was 6.4 weight percent.

This example again illustrates the opera-bility and utility of the process of the present invention in which a compound of sulfur and a compound of halogen are 40 added simultaneously. A high yield of hydroisomeri'zed hexane of high octane number was obtained at a moderate temperature under economical processing conditions.

We claim as our invention:

1. A process for the hydroisomerization of an isomerizable organic compound which comprises contacting said organic compound with hydrogen at hydroisomerization conditions in the presence of a hydroisomeriz-ation' catalyst comprising a hydrogenation component deposited on an acid-acting support, adding to the organic compound prior to said contacting a sulfur compound to control hydrocracking and a halogen compound to control hydroisomerization, and recovering the resultant prodnot.

2. A process for the hydroisomerization of an isomerizable saturated hydrocarbon which comprises contacting said saturated hydrocarbon with hydrogen at hydroisomerization conditions in the presence of a hydroisomerization catalyst comprising a hydrogenation component deposited on an acid-acting support, adding to said hydrocarbon prior to said contacting a sulfur compound to control hydrocracking and a halogen compound to control hydroisomerization, and recovering the resultant product.

3. A process for the hydroisomerization of a less highly branched chain parafiin hydrocarbon to a more highly branched chain paraffin hydrocarbon which comprises contacting said less highly branched chain parafiin hydrocarbon with hydrogen at hydroisomerization conditions in the presence of a hydroisomer-ization catalyst comprising a hydrogenation component deposited on an acid-acting support, adding to said hydrocarbon prior to said contacting a sulfur compound to control hydrocracking' and 'a halogen compound to control hydroisomerization', and recovering the resultant product.

4. A process for the hydroisomerization of an isomerizable organic compound which comprises contacting said organic compound with hydrogen at hydroisomen'zation conditions in the presence of a hydroisomerization catalyst comprising a platinum group metal deposited on an acid-acting support, adding to the organic compound prior to said contacting a sulfur compound to control hydrocracking and a halogen compound to control hydroisomerization, and recovering the resultant product.

5. A process for the hydroisomerization of an isomerizable saturated hydrocarbon which comprises contacting said saturated hydrocarbon with hydrogen at hydroisomerization conditions in the presence of a hydroisomerization catalyst comprising a platinum group metal deposited on an acid-acting support, adding to said hydrocarbon prior to said contacting a sulfur compound to control hydrocracking and a halogen compound to control hydroisomerization, and recovering the resultant product.

6. A process for the hydroisomen'zation of a less highly branched chain paraffin hydrocarbon to a more highly branched chain paraflin hydrocarbon which comprises contacting said less highly branched chain paraf fin hydrocarbon with hydrogen at hydroisomerization conditions in the presence of a hydroisomerization catalyst comprising a platinum group metal deposited on an acidacting support, adding to said hydrocarbon prior to said contacting a sulfur compound to control hydrocracking and a halogen compound to control hydroisomerization, and recovering the resultant product.

7. A process for the hydroisomerization of an isomerizable organic compound which comprises contacting said organic compound with hydrogen at hydroisomerization conditions in the presence of a hydroisomerization catalyst comprising platinum deposited on an acid-acting support, adding to the organic compound prior to said contacting a sulfur compound to control hydrocracking and a halogen compound to control hydroisomerization, and recovering the resultant product.

8. A process for the hydroisomerization of an isomerizable saturated hydrocarbon which comprises contacting said saturated hydrocarbon with hydrogen at hydroisomerization conditions in the presence of a hydroisomeriztaion catalyst comprising platinum deposited on an acid-acting support. addin to said hydrocarbon prior to said contacting a sulfur compound to control hydrocracking and halogen compound to control hydroisomerization, and recovering the resultant product.

9. A process for the hydroisomerization of a less hi hly branched chain paraflin hydrocarbon to a more hi hly branched chain paraflin hvdrocarbon which comnrises contacting said less hi hly branched chain paraflin hvdrocarbon with hydro en at hydroisomerization conditions in the presence of a hydroisomerization catalyst comprisin platinum deposited on an acid-acting support, adding to said hydrocarbon prior to said contacting a sulfur compound to control hvdrocracking and a halo gen compound to control hvdroisomerization, and recovering the resultant product.

l0. A process for the hvdroisomerization of an isomerizable or anic compound which comprises contacting said organic compound with hydrogen at hydroisomerization conditions in the resence of a hydroisomerization catalyst comprising platinum deposited on alumina containing combined halogen, adding to the organic compound prior to said contacting a sulfur compound to control hydrocracking and a halogen compound to control hydroisomerization, and recovering the resultant product.

11. A process for the hydroisomerization of an isomerizable saturated hydrocarbon which comprises contacting said saturated hydrocarbon with hydrogen at hydroisomerization conditions in the presence of a hydroisomerization catalyst comprising platinum deposited on alumina containing combined halogen, adding to said 20 hydrocarbon prior to said contacting a sulfur compound to control hydrocracking and a halogen compound to control hydroisomerization, and recovering the resultant product.

12. A process for the hydroisomerization of a less highly branched chain paratfin hydrocarbon to a more highly branched chain parafiin hydrocarbon which comprises contacting said less highly branched chain paraifin hydrocarbon with hydrogen at hydroisomerization conditions in the presence of a hydroisomerization catalyst comprising platinum deposited on alumina containing combined halogen, adding to said hydrocarbon prior to said contacting a sulfur compound to control hydrocracking and a halogen compound to control hydroisomerization, and recovering the resultant product.

13. A process for the hydroisomerization of an isomerizable organic compound which comprises contacting said organic compound with hydrogen at hydroisomerization conditions in the presence of a hydroisomerization catalyst comprising platinum deposited on alumina containing combined fluorine, adding to the organic compound prior to said contacting a sulfur compound to control hydrocracking and a halogen compound to control hydroisomerization, and recovering the resultant product.

'14. A process for the hydroisomerization of an isomerizable saturated hydrocarbon which comprises contacting said saturated hydrocarbon with hydrogen at hydroisomerization conditions in the presence of a hydroisomerization catalyst comprising platinum deposited on alumina containing combined fluorine, adding to said hydrocarbon prior to said contacting a sulfur compound to control hydrocracking and a halogen compound to control hydroisomerization, and recovering the resultant product.

15. A process for the hydroisomerization of a less highly branched chain paraflin hydrocarbon to a more highly branched chain paraflin hydrocarbon which comprises contacting said less highly branched chain parafiin hydrocarbon with hydrogen at hydroisomerization conditions in the presence of a hydroisomerization catalyst comprising platinum deposited on alumina containing combined fluorine, adding to said hydrocarbon prior to said contacting a sulfur compound to control hydrocracking and a halogen compound to control hydroisomerization, and recovering the resultant product.

16. A process for the hydroisomerization of n-butane which comprises contacting said n-butane with hydrogen at hydroisomerization conditions in the presence of a hydroisomerization catalyst comprising platinum deposited on alumina containing combined fluorine, adding to the n-butane prior to said contacting a sulfur compound to control hydrocracking and a halogen compound to control hydroisomen'zation, and recovering the resultant product.

17. A process for the hydroisomerization of n-pentane which comprises contacting said n-pentane with hydrogen at hydroisomerization conditions in the presence of a hydroisomen'zation catalyst comprising platinum deposited on alumina containing combined fluorine, adding to the n-pentane prior to said contacting a sulfur compound to control hydrocracking and a halogen compound to control hydroisomerization, and recovering the resultant product.

118. A process for the hydroisomerization of n-hexane which comprises contacting said n-hexane with hydrogen at hydroisomerization conditions in the presence of a hydroisomerization catalyst comprising platinum deposited on alumina containing combined fluorine, adding to the n-hexane prior to said contacting a sulfur compound to control hydrocracking and a halogen compound to control hydroisomerization, and recovering the resultant product.

19. A process for the hydroisomerization of 2-methylpentane which comprises contacting said Z-methylpentane with hydrogen at hydroisomen'zation conditions in the presence of a hydroisomerization catalyst comprising platinum deposited on alumina containing combined fluorine, adding to the Z-methylpentane prior to said contacting a sulfur compound to control hydrocracking and a halogen compound to control hydroisomerization, and recovering the resultant product.

20. A process for the hydroisomerization of methylcyclopentane which comprises contacting said methylcyclopentane with hydrogen at hydroisomerization conditions in the presence of a hydroisomerization catalyst comprising platinum deposited on alumina containing combined fluorine, adding to the methylcyclopentane 22 prior to said contacting a sulfur compound to control hydrocracking and a halogen compound to control hydroisomerization, and recovering the resultant product.

References Cited in the file of this patent UNITED STATES PATENTS 2,288,336 Welty et a1 June 30, 1942 12,604,438 Bannerot July 22, 1952 2,642,384 Cox June 16, 1953 2,659,692 Haensel et a1. Nov. 17, 1953 2,766,302 Elkins Oct. 9, 1956 2,798,105 Heinemann ct a1. July 2, 1957 2,853,435 Evering et a1 Sept. 23, 1958 

2. A PROCESS FOR THE HYDROISOMERIZATION OF AN ISOMERIZABLE SATURATED HYDROCARBON WHICH COMPRISES CONTACTING SAID SATURATED HYDROCARBON WITH HYDROGEN AT HYDROISOMERIZATION CONDITIONS IN THE PRESENCE OF A HYDROISOMERIZATION CATALYST COMPRISING A HYDROGENATION COMPONENT DEPOSITED ON AN ACID-ACTING SUPPORT, ADDING TO SAID HYDROCARBON PRIOR TO SAID CONTACTING A SULFUR COMPOUND TO CONTROL HYDROCRACKING AND A HALOGEN COMPOUND TO 